Chronometric instrument



oct. 14, 1941.

' H. HIBBARD I CHRONOMETRIC INSTRUMENT Filed Dec. 4, 1957 l 4 Sheets-Sheet l B20. y@ m41 0t- 14, 1941, F. H. HIBBARD CHRONOMETRIC INSTRUMENT Filed Dec. 4, 19:57` 4 sheets-sheet 2 Oct. 14, 1941. F H. HIB'BARD 2,259,309

cHRoNoMETRIc INSTRUMENT Filed Dec. 4, 1937 4 Sheets-Sheet 4 n x n HII 53 51.15l v 54y 53y Bijt. @(4a 2) mail A T TORNEV Patemed 0er. 14, 194'1 /cnaoNoMETmc INSTRUMENT Frank n. nibbara, Mountain Lakes, N. J., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y.,'a corporation of New York Application December 4, 1937, Serial No. 178,177

2 Claims.

This invention relates to testing devices and more particularly to a device for measuring and recording the operation ofwatches, clocks and like time mechanisms.v

The object of the invention is to provide a testing device of thetype above referred to which will be simple, convenient in use and which will give an accurate indication of the operation of a time mechanism under test in a minimum of time. v

According to this invention, the operation of a time mechanism is measured and recorded on a paper strip inthe form of successive marks representing the vibrationsI produced by the time mechanism under test. Actuating means is provided i'or 4rotating the paper strip at a speed per unit oi' time correspondingto the occurrence of successive vibrations in a standard time mechanism. The paper strip is provided with time lines disposed across its length and in the direction .of ymovement of an electro-magnetically operated recording means in its movement as imparted by a standard, such recording means in turn operating a stylus or marker according to the vibrations produced by the time mechanism under test for printing suh time marks on the paper strip, the deviations of. time marks as read with reference to the direction of the time lines on the paper strip being an indication of the inaccuracies in the Aoperation of the timepiece under test. The mechanical vibration of the 'timepiece under test are translated into electrical Fig. '1 is a view similar to that of Fig. 6 showing the marker-driving mechanism in the disengaged position;

Fig. 8 is an end view showing one of the supports for the spool of the carbon ribbon;

Fig. 9 is a longitudinal cross-sectional view of i the carbon ribbon spool taken on line 9-9 of the casing shown in section with a rubber pad shownv anchored therebetween; and

Figs. 13, 14 and 15 are examples of records made according to the operation of the recorder of the invention.

In the drawings I0 is a plate which is mounted on a plurality of rubber pads il and i2, in turn resting on two inwardly and parallelly disposed peripheral rims i3 and i4 formed .with the casing or base portion i5, the rubber pads Il being held in place by a number of pins PS shown in impulses which are transmitted to the electromagnetic device through a suitable ampliiier circuit. i

Other novel features of the invention and other advantages will appear from the following description and by the claims appended thereto, reference being had to the accompanyingvdrawings, in which:

Fig. l is a top assembly view showing the casing wit portions cut away;

Fig. Y is a front view showing the casing and a number of operating parts with portions cut Way;

Fig. 3 is a right-hand view showing the casing with portions cut away and a number of operating parts in section; s l

Fig. 4 is a cross-sectional view taken on hne 4-4 of Fig. 2;

Fig. `5 is a view of the marker driving mechamsm;

Fig. 6 is an end' view of Fig. 5 shown with the marker-driving mechanism in the engaged position;

Figs. 1 and 12 while the pads i2. are held by screws I3 as shown in Fig. 1.

The base portion i5 and the top portion I6 are provided with peripherally disposed interfltting .v passing through rubber bushings BS and on this plate is mounted a U -shaped bracket il shown in Figs. 1, 2, 3 and 4, provided for supporting a rotatable shaft i8 having a lead screw portion LSP. On one end of this shaft is securely mounted a drulri 22 having knurled peripheral ridges K and K1 for manually rotating it and on the opposite end of shaft I 8 is secured a gear i9 disposed in engaging relation with a pinion 20 securely mounted on one end of the armature shaft of a constant speed motor 2i, the speed ratio of gear I9 and pinion 20, considering the speed of motor 2|, b :ing such as to rotate the drum 22 at a speed of five revolutions per second or one turn for each beat of a standard time corded. This paper strip is wound on a spool t@ in turn mounted on the shaft i@ concentric to .and 2t shown in Figs. 2, i and 5, each provided with studs 29 and il@ laterally exten `there-- from for loosely mounting the il-shaped, grooved pulleys '2l and 2t provided tor supporting a rod 8i. On one end oi this rod is secured a lever member LM, which extends upwardly therefrom or receiving at its free end a comb or nut 32 shown in Figs. l, 2, 5, 6, 'l and il inthe form ol a U-shapeol leather stripwhich is securedly held at the tree end of lever member LM by a bolt 33, the ends or the leather strip being formed with tif-shaped grooves for engaging the lead screw portion LSP of shaft it, as shown in liigs.v d and il.

On the other end 'oi rod @i is secured, as by welding, a lever member i3d, shown in Figs. l, 2, 5, 6 and 7, having its upright extending end proiecting vthrough a slot @ti in the plate i@ for mounting a handle il@ provided for imparting a mail angular movement to the rod 3i for moving the nut 32 out of engaged relation from the lead screw portion LSP' of shaft i@ and manually imparting a longitudinal movement to this rod on the rollers 2l and 2t for moving the nut 32 in starting' position on the lead screw as shown in Figi` at the be r f.. 1 oi each recording. operation,lsuch starting position being defined by a stop member STO shown in Figs. l,- 2 and 5, and on the rod 3i at a point between the brackets 25 and 2li is secured, as by welding, one end of an inverted U-shaped bracket il which is-pr1 vided for mounting the heel-piece il@ of a magnet dit, an amature il@ being mounted on the heelpiece 38 on a so-called imiie .edge pivot where it is retained in adiustedposi'tion thereon by a aeeaeoe v er screws sty while the supporting shaft orspsol 5in is provided with knurled knobs Ka and Ks for manually rotating this -spooi as to present a fresh portion oi the carbon ribbon it in juxtaposition to marker it after a certain number of recording operationa v The carbon ribbon it is frictionally held from unwlnding on the spool. ein by a springt@ car- /Mried by a plate in turn'pivoted on the up= rights 53 `and Sty. with the free ends of spring Elfi resting von a lmurled wheel KW keyed on shaft SH, the longitudinal movement of shaft SH being prevented by the support Eby engaging a collar CR. formed in the hub of iinurled knob Ks.

, Plate bt extends tangentially tothe drum 22,

where it may be held against the tension ofspring 5d by a screw CS shown in Figs. l, 2, 3, t and 9 engaging the support 53;'. Thelront edge of plate 55 is bent downwardly to serve as a e edge against which that portion or the paper strip with the printed record thereon is detached from its spool 5t in the drum 22, while the loosening of screw CS permits the pivotal movement of plate 55 into a substantially vertical position for the removal or insertionof spool 5in and its supporting shaft'Slon supports lili and Sty.

The support for the. timepiece consists or s' j bracket Eil, shown in Figsi l, 2 and 3, pivotally mounted on the upright eilt-,ending lug portion oi' an angle-shaped supporting plate tit. bracket is frictionally held in adjusted angular vposition on the lug portion of pla @t by a coiled spring 5s and the lower disposedarm of bracketl El is provided with a semi-circular rim for t@ and a screw t3 which .engages a clearance hole m lug trof bracket et and animated hole m the lug et of heel-piece 38 is provided for adjusting a marker in the form of a pointed rod Q5 relative to the. turning axis of drum 22, this marker being 'carried by the armature 3Q and retained in operative relation thereon by a spring itt while a leaf spring member LS which has one oi` its ends secured to the heel-pieceiiil is pro- 4vided for holding the marker 46 vat this endv and to serve as retractile spring for the marker'and its actuating-'armature 3Q, the weight of magnet '40 and its associated operating parts tending to rotate the rod 3l on the pulleys 2li and 2b for normally holding the nut 32 in engaged relation with lead screw portion LSP of shaft it.

A carbon ribbon 4t, shown in Figs. 3 and 4, is

y interposed between the paper strip P carried by l spring arms .5I vand 52 shown in Fig. 2 secured to the underside of the plate l0, as by rivets RS, the other end of the carbon ribbon being coiled on-a spool il, shown in Figs.' 3,*4, 8 and Qhaving for receiving the timepiece TP asshown in Figs. 2 and '3, the timepiece"` being securely held thereon by'a spring pressed plunger @il having at its lower end a disc portion (t3 to which is secured a similarly shaped pad Sli 'of soft material engaging the crystal of the timepiece.

The plate t8, asishown in Figs. i and clampedbetween four sets of rubber-.b .GEL (it, ti and 5t, and each set is secured to a supporting plate t@ by screws CS1, CS2, CS: and CSi. 'I'his plate rests on a peripheral rim-ld formed with the casing portion it and is secured thereon by a number of screws li. y

0n plate 5t is mounted an electromagnetic pick-up device PD provided for translating the mechaxcal vibrationsof the timepiece'TP into electrical impulses which are received by magnet it through an ampliner circuit' (not shown) for impartingv longitudinal movements to marker it at a frequency corresponding to the beats of the timepiece TP under test. `The vibrations of the timepiece are imparted to the electromagnetic.

pick-up or translating device PD by a rod 'i2 shown in Figs. l and 3 having at one ofits ends a disc portion 'i3 in' contact with the watch case ofy the timepiece and its' opposite end threadedly engages the armature it o i' the magnetic pickup device. i

A switch t@ shown in Figs; l, 3 and 10 is se cured to the under side of plate i0. VThis switch is provided with a plunger member 8i actuated byv an arm 82 having one of its ends 'secured' to a leaf spring member 83 with its free end extending in operable relation with lug d2 of the inverted U-shaped bracket 31, this switch being provided for opening the motor circuit when the This ais-- ASW and MSW shai'tv I8 and P, as imparted by the lead screw gears i9 and 20, considering the its starting point,

marker 4l has traversed the record sheet. i. e'.,- at the conclusion of each recording operation.Y

In a typical example of operation. the watch to be tested is placed on the felt pad li with the center portion of the watch case in contact with the disc 13 at the end of rod 12 where it is held by the spring-pressed plunger 82, as shown in Figs. 1, 2 and 3. With the record strip clamped o the drum 22, as shown in Fig, 4, and the nut Il, together with the marker Il, in the starting position against the stop S'IO, shown in Figs. 2 and by the operation of-handle 3B. the switches are operated for energizing the amplier and motor circuits, respectively. The operation of mo or 2| is eii'ective to rotate the thereby the drum 22 simultaneously with the longitudinal movement of rod Il and that of the marker 4l across the paper strip portion LSP of shaft Il. As above stated, the speed ratio of the revolutions per minute of motor 2|. is such as to rotate the drum 22 at a speed of five revolutions persecond or one turn for each beat of a standard timepiece while a pitch for the lead screw portion of shaft Il is so chosen as tomove thel marker Il across the paper record in a lapse of time of thirty seconds, when the switch Il is moved to its open position through the movement of its operating arm l2. for stopping the constant speed motor 2|.

'I'hat portion of the paper on which the record is printed may be detached from the spool Il by bringing it in contact with the knife edge portion of plate 5I and a new length of the stripsecured ori-the drum by the clips 23 and 2l, as above described.

As shown by the example of the record in 13, if the timepiece under testis correct, the

`record of its operation will appear as a series of dots disposed on or in line parallel to one ofthe time lines on the paper chart. In Fig. 14 the line of dots deviates a distance of two lines from 1 justable means engaging said `-cured to said moving means and a bracket sewith respect to its adjacent time lines, indicating that the timepiece under test is ten seconds "fastper day. while in Fig. l5 the line of dots is shown deviatedva distance of two lines inthe opposite direction to that of Fig.

'tested is ten seconds s1ow" vly of the direction of movement of and having a part netic means and another part for guiding the 14, indicating that the operation of per day. In the device of the invention the pivoted bracket or support l1 for the timepiece permits the recording of the timepiece under test in a number of angular positions as to simulate the carrying of the timepiece by a person, thus permitting an accurate adjustment of a timepiece in. a minimum of time and adjusting operations.

What is claimed is: 1. In a chronometric instrument having means for moving a record sheet, a marking device and means for moving the marking device transversesheet, said marking device comprising a stylus land electromagnetic means for bringing said stylus into engagement with the record sheet, the improvement which comprises a bracket secured to said moving y,means and a bracket securely mounted on said first bracket and having a part supporting the electromagnetic means vand an` other part for guiding the stylus. said rst bracket having a flexible portion, and mutually'adbrackets for flexing the first bracket and thereby moving the second bracket to adjust said stylus relative to said record sheet.

2. In a chronometric instrument having a rotatable drum on which a record sheet is support- .ed, a marking device, and means for moving the marking device parallel to the axis of rotation of the drum. said marking device comprising a stylus and electromagnetic means for bringing said stylus into engagementwith the record sheet, the improvement which comprises a bracket securely mounted on the first-mentioned bracket supporting Asaid electromagstylus, said first-mentioned bracket having a flexible portion, and manually adjustable means engaging both brackets for flexing the first bracket andthereby moving the second bracket to adjust said stylus in a direction perpendicular to the axis of the drum. g

' FRANK-H. HIBBARD.

the timepiece t the record 

